Thread: Need Help Identifying Transmission Whine

Alright, I know these questions usually start out with not enough info and usually draw tons more questions in response, so let me try to be as complete as possible with what I know so far. So appologies in advance for being so long. Also I have searched all the other posts regarding trans noise and none seem to have been the same problem so far, so I am posting with that in mind. Here goes:

I purchased this 2001 GP GT about 5 months ago. It had 131,000 miles on it. When I bought it it was just starting to exhibit the classic intake gasket leak, so I replaced the upper and lowers and did a coolant flush, and at the same time I cleaned the engine (externally) with Gumout Steam Clean in a can. I cleaned the engine before I did the intake, and again after it was complete. Very soon after completeing this repair, I started to notice an intermittent whine, like a pump noise. At first I figured I cleaned some gunk off something that really missed it while cleaning the engine. As the noise started to become more frequent and pronounced, I guessed that it was the power steering pump. I based it on the type of pump squeal type sound that I was hearing, and a test that I did where when it was making the noise I turned the wheel lock to lock, and the squeal stopped momentarily until I released the wheel. It did this repeatedly about 4 or 5 times, and each time I hit the lock, the squeal would stop. So I replaced the pump and flushed the power steering fluid. The squeal was unchanged.

After thinking about it, I had a hunch that maybe it was the transmission. I started to also notice a very faint slip at very low throttle, less than 7 or 8% according to the TPS. I did a trans flush (including using seafoam just before the flush), dropped the pan and installed a new filter and gasket, and installed an auxillery trans cooler. The trans fluid needed a flush anyways, so that part was just PM. And the trans cooler was just a good idea as it seemed to run hot to me. Usually the same as the engine or a few degrees hotter before the cooler. Now after the cooler it runs at least 15 degrees cooler than the engine, and usually about 30-40 degrees cooler. This allowed me to make a new observation, the squeal only happens when the trans fluid gets warm, around 130-140 degrees from what I have observed. It does not squeal on a cold start when the car has been sitting all night. Turning the car off and restarting it has no effect as long as the fluid is still warm. It will squeal in any gear, even Neutral or Park. It is the same noise while driving too, although it gets harder to hear while driving because of wind and road noise. It dosent really get louder with engine RPM, but it does change tone slightly, like you would expect a pump squeal to I guess. It seems to quiet itself when the engine is completely at idle, but as soon as you nudge the gas the slightest bit it starts to squeal again. If the trans fluid is too hot, say up to 180-190 degrees it is less likely to stop squealing at idle, or take longer at idle to quiet down. This is an improvement over what it was doing before the flush, which was squealing non-stop regardless of idle or not, but I think that may be becuase the trans is running cooler now, not becuase of the fluid, although it may be a bit of both, not sure. Also that faint slip at low throttle has improved, and I have not noticed it since the flush. I did the flush about 300 miles ago. The car now has around 134500 miles. The car runs and drives and shifts perfectly now, and if not for the noise would have no other issues.

So what are your thoughts, could this be an oil pump? Could it be another trans component? I am not 100% sure it is the trans making the noise, but the corrolations with trans temp seem to point to that. Any help in further testing or isolating the noise, or opinions on what the noise is would be greatly appreciated.

Thanks In Advance!

Thanks for the speedy reply. I have a stethoscope, but it is up north. I will be getting it this weekend and checking it out further. I also will probably pull the belt just to isolate all the pullies and see if it goes away that way. I will report back on Monday with any new findings. Hope to have some more info.

P.S. Yes it makes the noise while in gear and stopped too.

Alright, here are my findings from this weekend:

I listened to all of the pullies, alternator, power steering, water pump, idler, a/c compressor, and none of them seemed bad. I was pleasantly surprised to hear the water pump makes a soothing swooshing type noise through the scope.... kinda helped to relax me with all this aggravation But just to be sure, I did take the serpentine belt off and ran the engine (briefly) with no belt, and the noise persisted, so I am sure it is nothing being driven from the belt. (Wish I would have thought to do this before I replaced the PS pump and wasted that time and $).

Next, I moved on to the transmission, I listened to the bell housing, and the noise was a very mild (faint & non-distinct) grumble, did not sound like a whine through the scope, but more like a bearing possibly? The noise seemed slightly louder to the far driver side of the housing, as opposed to clsoer to the middle of the housing straight down from side of the engine intake. I dont know, as I am new at using the scope to listen for noises, so I am not sure exactly what I should be hearing should sound like. I listened through the trans pan under the car, and it was very similar to the bellhousing from the top. Then I listened to the trans cooler lines (the metal ones right near where they exit the trans) and I could hear a distinct grumble through both lines, kind of sounded a little like a bad bearing type noise, or a bearing with one ball removed and replaced with a small rock instead. The noise was loudest near the trans, and inauduble in the trans cooler lines at the radiator (they are isolated by rubber hose). I think this tells me the noise is certainly in the trans, and not just the coolant flow through the lines. And very near where the lines go into the trans.

There is no difference in the noise regarding hard or soft accelleration, so I do not think it is the torque converter, at least these tests dont appear to point in that dirrection I dont think, but I will deffer final judgement to the expert.

When it is making the noise, I put it in 1st, and there was no difference in the noise. It was still present, but no louder or softer.


So here is my 3 part question:

1. What in your opinion is bad and/or a likely culprit? Is there a way to verify this before or during the repair so I dont get it back together and still hear the whine?

2. Is it servicable through removing the side cover, or do I have to pull the whole trans from the vehicle?

3. If I choose to do this repair myself, are there any special tools I will require that a normal well stocked tool chest for someone that dosent do trans work wouldnt have?

was this problem ever solved? i may have a similar issue on a swapped tranny.

I came to the decision that due to the mileage, a tranny rebuild would most likely be the best course of action to take, and I did not want to make that kind of investment in that car. So I sold it as it was. I am fairly confident it was the valve sticking that was commanding max line pressure from the pump, I just never tried to replace it to verify because if I would have ended up going that far I would have wanted to rebuild the whole trans at that point anyway.

Really bringing up an old thread here but I believe I have the same or similar problem. It will make the noise in all gears, stopped or rolling, and sounds just like a power steering pump. Trans fluid level is fine, but I have noticed partial slip at low throttle like mentioned above . I have a video on my started thread if you need to hear the noise. Thanks in advance